g the
acts and language of very young children, data are obtained concerning
the native instincts of the child, concerning the genesis and
development of the different mental processes, and the relation of these
to physical development. A brief statement of the leading principles of
Child Study will be found in Chapter XXXI.

=C. Experimental Method.=--A third method of studying mind is known as
the _Experimental_ method. Here, as in the case of the ordinary physical
experimenter, the psychologist seeks to control certain mental processes
by isolating them and regulating their action. This may be effectively
done in the study of certain processes. For instance, by passing the two
points of a pair of compasses over different parts of the body, the
tactile sensibility of the skin may be compared at these different
parts. By this means it may be shown that the tip of the finger can
detect the two points when only one twelfth of an inch apart, while on
the middle of the back they may require to be two and a half inches
apart to give a double impression. The experimental method is often
used in connection with the objective method in Child Study.

PHASES OF CONSCIOUSNESS

=A. Knowledge.=--Although, as previously stated, the stream of
consciousness must at all times be looked upon as a unity, it will be
found upon analysis to present three more or less distinct phases. A
state of consciousness implies, in the first place, being aware of
something as an object of attention. In other words, something is seized
upon by consciousness as a presentation, and to the extent to which one
is aware of this object of consciousness, he is said to recognize, or to
know it. A state of consciousness is always, therefore, a state of
knowledge, or of intelligence. Thus, whether we perceive this chair,
imagine a mermaid, recall the looks of an absent friend, experience the
toothache, judge the weight of this book, or become angry, our conscious
state is a state of _knowledge_.

=B. Feeling.=--A conscious state is also a state of feeling. Every
conscious state has its feeling side, since it is a personal state, or
since the mind itself is affected toward its own state. Two men, for
instance, may know equally well the taste of a particular food, but the
taste may affect each one quite differently. To one the experience is
pleasant, to the other it may be even painful. Two boys may know equally
that a point has been scored by the visiting te